The present invention relates to industrial furnaces, and more particularly to means for protecting the casing of a furnace.
From time to time during the operation of industrial furnaces, and for various reasons, the burner blocks that are located in the furnace lining will crack. When this occurs it is not unusual for a combustible mixture of gas and air to flow backward from the front of the burner through the cracks in the block and refractory lining to burn along the outer surface of the lining and casing. When this occurs the furnace casing is damaged and the furnace refractory lining is damaged.
Gases can also flow in the other direction into the furnace, depending upon furnace pressure. Inward flow introduces excess air into the furnace at the burner to produce a change in flame characteristic from that desired. The flow is uncontrolled since the size of the cracks is indefinite and varies with time and furnace operation.
Various means of insulating and caulking around the back of burner blocks have been tried to prevent the flow of gases, without much success.